Isolated complexes of the amino acid arginine with polyether and polyamine macrocycles, the role of proton transfer

2017 ◽  
Vol 19 (46) ◽  
pp. 31345-31351 ◽  
Author(s):  
Juan Ramón Avilés-Moreno ◽  
Giel Berden ◽  
Jos Oomens ◽  
Bruno Martínez-Haya

Protonated arginine interacts with 12-crown-4 through the guanidinium side group. In the complex with the N-substituted analog cyclen, the dominant conformation is the result of the proton transfer from the carboxylic acid group of the amino acid to the macrocycle.

2014 ◽  
Vol 70 (9) ◽  
pp. o1008-o1008 ◽  
Author(s):  
M. Nawaz Tahir ◽  
Abdul Haleem Khan ◽  
Hazoor Ahmad Shad

The title Schiff base, C14H11NO3, crystallizes as a zwitterion (i.e.proton transfer from the carboxylic acid group to the imine N atom). The dihedral angle between the aromatic rings is 19.59 (6)° and an intramolecular N—H...O hydrogen bond closes anS(6) ring. In the crystal, inversion dimers linked by pairs of O—H...O hydrogen bonds generateR24(24) loops. The dimers are linked by C—H...O interactions, generating (211) sheets.


2014 ◽  
Vol 70 (4) ◽  
pp. o450-o450 ◽  
Author(s):  
A. Sankar ◽  
S. Ambalatharasu ◽  
G. Peramaiyan ◽  
G. Chakkaravarthi ◽  
R. Kanagadurai

In the title 1:1 adduct, C6H5NO3·C6H5NO2, both molecules are almost planar (r.m.s. deviations for the non-H atoms = 0.027 and 0.023 Å for 4-nitrophenol and 2-carboxylatopyridinium, respectively). The pyridine molecule crystallizes as a zwitterion (nominal proton transfer from the carboxylic acid group to the N atom in the ring). In the crystal, inversion dimers of the zwitterions linked by pairs of N—H...O hydrogen bonds generateR22(10) loops; two 4-nitrophenol molecules link to the dimer by O—H...O hydrogen bonds, generating a four-molecule aggregate. These are linked by C—H...O interactions, forming a three-dimensional network.


2006 ◽  
Vol 62 (7) ◽  
pp. o2751-o2752 ◽  
Author(s):  
Ting Sun ◽  
Jian-Ping Ma ◽  
Ru-Qi Huang ◽  
Yu-Bin Dong

In the title compound, C10H7N3O4·H2O, one carboxyl group is deprotonated and the pyridyl group is protonated. The inner salt molecule has a planar structure, apart from the carboxylic acid group, which is tilted from the imidazole plane by a small dihedral angle of 7.3 (3)°.


2014 ◽  
Vol 70 (12) ◽  
pp. o1242-o1243 ◽  
Author(s):  
Wei Tang ◽  
Neng-Hua Chen ◽  
Guo-Qiang Li ◽  
Guo-Cai Wang ◽  
Yao-Lan Li

The title compound [systematic name: 3β-hydroxylup-20(29)-en-28-oic acid methanol monosolvate], C30H48O3·CH3OH, is a solvent pseudopolymorph of a naturally occurring plant-derived lupane-type pentacyclic triterpenoid, which was isolated from the traditional Chinese medicinal plantSyzygium jambos(L.) Alston. The dihedral angle between the planes of the carboxylic acid group and the olefinic group is 12.17 (18)°. TheA/B,B/C,C/DandD/Ering junctions are alltrans-fused. In the crystal, O—H...O hydrogen bonds involving the hydroxy and carboxylic acid groups and the methanol solvent molecule give rise to a two-dimensional network structure lying parallel to (001).


2012 ◽  
Vol 13 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Dongho Kim ◽  
Yoomi Yoon ◽  
Ildoo Chung ◽  
Chanyoung Park ◽  
Jongwoo Bae ◽  
...  

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